1. Field of the Invention
This invention generally relates to a pump for dispensing parenteral fluid medication and, more particularly, to a pump which continuously dispenses such medication in small doses over an extended period of time.
2. Description of the Prior Art
In-hospital dispensing arrangements for continuously dispensing fluid medication in small doses over extended periods of time to a patient are well known. Typically, such dispensing arrangements are of the gravity-feed intravenous type, and require large-sized bottles, long tubing, adjustable valves and, in general, a fairly elaborate set-up which is relatively expensive and unwieldy such that the set-up is not readily transportable from place to place. Power-driven medication pumps are also known, but these are much more expensive and even less readily transportable. An in-hospital patient hooked up to such a gravity-feed intravenous and/or power-driven pump arrangement cannot easily leave his or her bed and, even if the patient desires to be ambulatory, it certainly is a handicap for the patient to try to walk with such an elaborate set-up connected to the patient.
There are many situations where an out-patient has to receive medication, preferably on a continuous basis. For example, diabetics are typically injected with a periodic, e.g. daily, insulin dose at discrete times during the day. It would be more desirable if the diabetic would not receive the insulin in one or several massive doses, but, rather, if the insulin were administered in small doses over an extended time period. For this purpose, since the average diabetic cannot spend the day hooked up to a gravity-feed and/or power-driven pump dispensing arrangement, different types of delayed-action insulin have been prescribed. Nevertheless, rather than having the diabetic inject himself or herself with slow-acting and/or fast-acting insulin, it would be preferable if the diabetic could receive the insulin slowly and continuously without the economic and mobility restrictions imposed by known elaborate and expensive pump dispensing arrangements.